Overheating analysis
Comprehensive assessments to prevent excessive indoor temperatures, ensuring occupant comfort and regulatory compliance using the simplified method.
From £150 · simplified method
Approved Document O · CIBSE TM59
Precision. Compliance. Confidence.
O-Reg Thermal was created to provide a smarter, more reliable approach to overheating compliance and dynamic thermal modelling.
- Assessments from £150
- Modelled to TM59 and Part O
- Reports written to be read by a planner
- Turnaround in days, not weeks
Part O is now the thing that holds a scheme up
As Part O regulations become increasingly critical in UK construction, we support developers, architects, and consultants with clear, accurate, and actionable analysis.
An overheating assessment that comes back as a bare pass or fail leaves you no further forward. Ours tells you which rooms are at risk, by how much, and what would fix them — so the next move is obvious rather than another round of guesswork.
Our approach
We go beyond basic calculations. Every project is delivered with:
- Accurate modelling using industry standards. Built to the methods the regulations actually name, with the assumptions stated so anyone checking can follow them.
- Clear, professional reporting. A document that a building control officer, a planner and a client can each read without a translator.
- Practical design recommendations. Changes that work on a real drawing — not a note telling you to reduce the glazing and leaving you to it.
- Fast and reliable turnaround. A date at the outset, and the report on that date.
Discover our thermal dynamic expertise
Learn how our consultancy ensures building compliance with TM59 and Part O through expert thermal dynamic modelling and analysis services.
Dynamic thermal simulation
Advanced simulations that predict building performance under varying conditions to optimise design decisions.
From £450 · full TM59 run
Energy modelling services
Detailed energy consumption forecasts to support sustainable development and efficient building operation.
Priced per scheme
What makes us different
We focus on solutions, not just compliance — helping you move forward without delays, redesigns, or uncertainty.
Assessments from £150
Cost-effective, consultancy-grade analysis. The price is agreed before the work starts and does not move once it has.
Proven compliance
Accurate modelling aligned with Part O and TM59, documented so that the people who have to sign it off can see how it was arrived at.
Tell us about the scheme
Send the drawings and a short description and you will have a price, and a realistic date for the report, the same working day.